Method of forming and applying screw caps to containers



TO CONTAINERS April 28, 1936. l.. R. N. cARvALHo v METHOD OF FORMING AND APPLYING SCREWy CAPS Filed Oct. 25,' 1954 INVENTOR.

Patented Apr. 28, 1936 METHOD F FORDIING AND APPLYING SCREW CAPS '.lO CONTAINERS l Leslie R. N. Carvalho, Toledo, Ohio, assignor to The Closure Service Company, Toledo, Ohio, a

.' corporation of Ohio Application October 25, 1934, Serial No. 749,899

3 Claims. (Cl. 226-86) My invention relates to screw caps for bottles, jars and otherv containers, and contemplates a nal forming of the cap after it has been initially applied to the screw threaded nish of the 5 container.

The usual method of applying a screw cap to a screw threaded bottle nish develops certain difliculties. on one side and fail to maintain the liner inperfect sealing-engagement. Again, the lacquer on the inside of the cap, or the intervening liner,

f is sometimes mutilated by some slight roughness or irregularity during the turningl movement of applying the cap on the finish of the bottle, thus l5 producing 1eakers. Another defect of the ordinary screw closure is that the 'uniformly rolled threads of the cap cannot take up the variations which develop in the molded threads of different containers even though produced on the same bottle machine.

To meet these objections, it has been proposed to draw the cap without threads, apply it to the finish of the bottle by top pressure, and While in this position, apply a rolling die which rolls the threads into the angeof the cap in con-4 formity with the threads of the container finish.

A cap of this type is superior to the ordinary screw cap, for the reason that uniform downward pressure is exerted on the liner to bring it into sealing engagementwith the top of the 1inish and avoid the creeping action that is likely to be imparted tothe liner in screwing the cap down on the jar and that oftentimes wrinkles the liner between the inside of the cap and the top of the bottle nish so as to prevent an even seal.

My present invention contemplates the similar procedure of applying the flanged cap to the container by direct down pressure, but at the 40 same time utilizing this pressure, instead of a' rolling die,.to collapsethe ange orskirt of the cap into the threads of the container to conform thereto, thus eiecting a perfect gripping action of thev cap upon and in sealing contact with the nnisn of, the container, from which,

however, it may be readily removed by an unscrewing movement like the ordinary screw cap, whenever it is desired to break the seal and expose the contents of the container.

5 An object of my invention is to provide a. cap

which will render a more perfect sealing engagement between the liner and the top of the finish, and in which the screw threads are given nal form by collapsing the depending flange of the cap inwardly against the threaded exterior of Frequently the caps will cock up the finish, with the result that each cap is made to fit accurately the individual nish to which it is applied, regardless of variations in the latter.

Further objects appear from the ensuing de-A 5 scription of the construction illustrated in the accompanying drawing in which:

Fig. 1 is a side elevation of my cap before applying it vto a container.

Fig. 2 is a vfragmentary sectional elevation of 10 the container, cap, sleeve and plate in assembled relation immediately prior to the application of. top pressure. Fig. 3 is a fragmentary sectional elevation of the container and' cap in sealed relation after l5 top pressure hasbeen applied and the plunger Fig. 4 is a side elevation of the cap in its completed form and removed from the containen Referring to Fig. 1 of the drawing, I 0 is the 20 I cap generally, including a circular top portion II4 and adepending flange or skirt I2. Within the cap is aliner I3 (Figs. 2 and 3). The upper part of. the ilange I2 has a slightly outturned bead I4 which may be plain or corrugated, as desired. 125 Below. the bead is a light continuous thread I5. The skirt terminates in a curled or wire edge I6.`

Referring, now, to Fig. 2, the cap is loosely tted to the nish I1 of a container, the. screw thread I5 of the cap engaging loosely the screw 30 thread I8 of the iinish. Due to this loose engagement, it is not necessarythat interior surface of the ange I2 conform to the variations in the container iinish. The cap is appliedto the finish and the wire edge I6 seats on the iln- 35 ishing ring I9 of the container, which is of the usual construction. It is to be particularly noted at this juncture, and is clearly shown in Fig. 2, that thetop portion II and the liner I 3 do not seat on the top of the iinish, the depth of the 40 skirt being suicient to hold the top portion and liner in spaced relation to the top o f the finish.

A sleeve v2li having a plate 2I movablev longitudinally thereof, is slipped over the cap and is" brought to rest on the finishing ring I9. The 45 sleeve is concentricto the container and cap, and is contiguous to the outermost part of the thread I5 and the wire edge I6. The plate is seated on the top portion II of the cap I Il.

' With application of top pressure from any suit- 504 able source (not shown), the plate 2,I moves downward and forces the `top portionand liner to seat on the top of the nish Il, as shown in Fig. 3. Simultaneously, the flange I2 is collapsed between the screw threaded nish I1 and the 55 tinuous thread I5 having been lightly drawn in the flange, as shown in Fig. 1, the flange will fold in process of collapse in a manner accentuating the bead I4 and the thread I5. As the sleeve 2li will prevent outward expansion of the folds, they are forced into the spiral recess between the ridges of the thread I5, and over the thread itself. Accordingly, after the application of top pressure on the cap, the ange will develop a thread conforming closely to the container finish, as shown in Figs. 3 and 4. The outturned bead I4, being the weakest part of the cap and having no support, readily collapses during the application of top pressure, allowing the liner to engage the bottle finish to form a tight seal.

In applying. the cap flange to the outer surface of the finish in the manner described, all turning of the cap on the finish is avoided. Thus, the lacquer on the interior of the flange is not scratched nor marred. Further, the cap is brought down at uniform pressure on all parts of the top surface of the finish so that the liner effects a tight seal therewith and no creeping or wedging action can take place. The cap is caused to fit the individual finish to which it is applied, and any irregularities present in the finish are compensated for inasmuch as the flange of the cap follows the contour of the finish.

Modifications may be resorted to spirit and scope of my invention.

y What I claim is:

1. The method of applying a cap having preformed threads outlined on the flange thereof to a threaded container finish, consisting in springing the cap loosely over the finish and applying top pressure thereto to collapse the cap onto the finish and thereby wholly form the cap 'threads to engage the nish threads, and coniining the threaded portion of the cap by a surrounding sleeve having a smooth interior surface maintained in a fixed position concentric witlr' said iinwithin the portion of the cap with sleeve 20. The outturnedbead I4 andthe conish during the said collapse of the cap onto the nish.

2. The method of attaching to a container having an exteriorly screw threaded neck portion, a cap having a top portion and a depending skirt formed with shallow screw threads corresponding in number and arrangement to the threads on said neck portion, which method comprises placing the cap on the container and supporting it with the top portion thereof spaced above the top of the container, surrounding the threaded a sleeve, and applying downward pressure to said top portion of the cap and thereby lowering it and simultaneously causing said top pressure to decrease the depth of said skirt and thereby deepen said shallow threads, causing each said deepened thread to conform to a corresponding thread on the container.

3'. The method of attaching to a container having an exteriorly screw threaded neck portion, a cap having a top portion and a depending skirt formed with shallow screw threads corresponding to the threads on said neck portion, which method comprises placing the cap on the container and supporting it with the top portion thereof spaced above the top of the container. and applying downward pressure to said top portion of the cap and thereby lowering it and simultaneously causing said top pressure to decrease the depth of said skirt, and confining the threaded skirt against outward expansion during said lowering of the top portion of the cap, by a surrounding sleeve having a smooth interior surface maintained in ilxed position concentric with said neck portion of the container during said collapse of the cap onto the finish, and thereby causing a deepening of said shallow threads and a conformationthereof to the threads on the container.

LESLIE R. N. CARVALHO. 

